1. Field of the Invention
This present invention relates to a mobile communication terminal and a wireless communication module thereof.
2. Description of Prior Art
As the mobile communication technology is rapidly developing, the mobile communication terminals are provided with a space for great improvement. There are two main implementing solutions for the mobile communication terminals.
One solution integrates the chipsets of the base band and radio-frequency circuits. This solution employs a standard single or double circuit board(s) to integrate the periphery circuits including, for example, keyboard, LCD, SIM card and so on. Generally, mobile phones employ this solution. However, such a solution needs a complex design for radio-frequency and base band circuits and the functions of mobile communication have to be completely and finely tested. There are therefore the disadvantages of significantly increasing the cost of development and manufacture and the elongated development period which are adverse to the speedy renewal of the mobile communication products.
The other solution modularizes the wireless communication circuits to design wireless communication modules. The designed modules are welded onto a host. Radio-frequency transmission/reception, base band encoding/decoding and the run of protocol stack are implemented by the stable and mature wireless communication modules. The periphery circuits such as keyboard, LCD, SIM card and the likes perform their control functions through the host. This solution is mainly used in personal information products such as personal digital assistants (PDAs) and notebook computers to perform wireless communication functions, but is rarely used in mobile phones at present. For example, in PDA, the wireless communication module is typically welded onto the main board of the host. Also, in some cases, both the wireless communication modules and the host are directly designed on a single printed board and are connected to each other with interface circuits. Such wireless communication modules are also installed inside the host and do not support plug and play neither. Further, there is no standardization of the interface among different manufacturers. The hardware configuration thereof is shown in FIG. 1 which is a schematic diagram showing the hardware configuration of PDA for implementing the wireless communication functions in a prior art. Herein, a wireless communication module 100 includes a radio-frequency antenna socket 102, a radio-frequency processing unit 103, a base band processing and power supply managing unit 104, a memory 105 and so on. The base band processing and power supply managing unit 104 is connected to the radio-frequency processing unit 103 and the memory 105. The base band processing and power supply managing unit 104, the radio-frequency processing unit 103 and the memory 105 collaborate to perform radio-frequency transmission/reception, base band encoding/decoding and the run of protocol stack. The radio-frequency processing unit 103 and the base band processing and power supply managing unit 104 are connected to an interface circuit 111 of a host 110 through an interface circuit 101. The host 110 mainly includes a battery and power supply managing unit 112, a micro control unit (MCU) 113, a liquid crystal display (LCD) 114, a speaker and a microphone (SPK & MIC) 115, a keyboard 116, a SIM card unit 117, a memory 118, a radio-frequency antenna plug 121, and other parts. The battery and power supply managing unit 112 supplies power to the wireless communication module 100 and the other parts of the host 110. The micro control unit (MCU) 113 controls interface communication to perform foundational functions such as LCD display, keyboard control and charging/discharging management. The liquid crystal display (LCD) 114 displays a man-machine interface and performs information interactivity and controls the operations between the user and the PDA. The speaker and the microphone 115 output and input audio signals. The memory 118 stores host program, ring tones, short messages and phone book. The radio-frequency antenna plug 121 connects a radio-frequency antenna 120. The signals transmitted between the interface circuits 101 and 111 comprise power supply signals, control signals, SIM card signals, data and command signals and audio signals. The data and command signals can be transmitted through a standard serial communication interface.
FIG. 2 is a schematic diagram showing the software architecture of the PDA for implementing the wireless communication function in prior art. A wireless communication module 200 is composed of software modules such as an interface driver program 201, a CSD protocol 202, an AT command interpreter 203, a PPP protocol 204, an IP relay 205, a GSM/GPRS protocol stack 206 and a physical layer 207. These software programs are stored in the memory 105 of the wireless communication module 200 and executed by the base band processing and power supply managing unit 104 in the wireless communication module 200.
Corresponding to the wireless communication module, the host 210 is composed of software modules such as an AT command/data processing program 211, an IP application program 212, a TCP/IP protocol 213, a PPP protocol 214 and an interface driver program 215. These software programs are stored in the memory 118 of the host 210 and executed by the MCU 113 in the host 210.
In PDAs with the same model, the interface driver program 201 in the wireless communication module 200 corresponds to the interface driver program 215 in the host 210. The PDAs with different models may employ different interfaces. Therefore, the interface driver programs for the PDAs with different models are somewhat different. Typically, the interface is a serial communication interface.
The basic operation flow with the above software architecture is as follows. During the transmission of commands, if an application program on the host side intends to interact with a network, a corresponding message is firstly packaged into an AT command by using the AT command processing program. The packaged message is then sent through the interface driver program. On the side of the wireless communication module, after this module receives the AT command through the interface, the AT command is interpreted into an actual protocol message at the AT command interpreter layer, and then is sent to the protocol stack.
During the transmission of data, the data stream is transparently transmitted between the host side and the side of the wireless communication module though the interface, and is not processed by the AT interpreter layer. The user may select CSD or GPRS for data transmission.
(1) If CSD is selected to transmit data outward, the AT command/data processing program on the host side sends an AT command to request the establishment of a communication link through a serial port. After receiving the AT command through the serial port, the AT command interpreter on the side of the wireless communication module performs corresponding processes, and controls the CSD protocol and the GSM/GPRS protocol to make a connection of the data communication link. After establishing the connection, the AT command interpreter on the side of the wireless communication module then returns the network information to the AT command/data processing program on the host side. Then, the AT command/data processing program may transmit the data.
(2) If GPRS is selected to transmit data outward, similarly, the AT command/data processing program on the host side, the AT command interpreter and the GSM/GPRS protocol on the side of the wireless communication module are responsible for the establishment of a link connection. When the connection is established, the data may be transmitted. The transmission of data is achieved by the IP application program, the TCP/IP protocol, and the PPP protocol of the host and the PPP protocol, the IP relay of the wireless communication module.
This solution provides significant advantage that only the design for the host needs to be modified. That is, it is unnecessary repeatedly to design the radio-frequency (RF) and most of the base band circuits in the mobile communication terminals. Further, the research and development period is shortened so that the manufacturers put new products into market more rapidly. However, since the wireless communication module interfaces produced by different manufacturers are not standardized at present, the development for software and hardware are limited in many aspects.
With the development of mobile phones, more and more functions are being provided, and the performance of the mobile phones is getting better and better. For example, more vivid music, color display screen, more fashionable designs, and multimedia applications are provided. The users are largely motivated to change their mobile phones due to these factors. And thus, a disadvantage common to the above-mentioned two solutions becomes apparent. Since both the wireless communication circuit and the mobile communication module are fixedly welded on the printed board, therefore the mobile phone as a whole is thrown away when a user changes his/her mobile phone due to its housing or additional functions. That is, the wireless communication module which can be repeatedly used is also thrown away, resulting in a great waste of resources.
As to other mobile terminals, since the wireless communication interfaces are not standardized, each mobile terminal is equipped with one wireless communication module, which also results in a waste of resources.